The present invention relates in general to the field of conveyors of articles, such as, for instance, belt conveyors and chain conveyors, for example, although not exclusively, of the type employed for transporting bottled drinks and similar products. The invention more particularly relates to guides used in such conveyors of articles for the containment and the routing of the transported articles.
In conveyors of articles the use of guides is known to ensure the containment and the correct routing of the transported articles. Such guides are particularly necessary in correspondence of curves and bifurcations of the transport line, for instance in correspondence of accumulation stations, where a single flow of transported articles needs to be separated into two or more separate flows, for example to prepare the articles to the packaging.
The use of roller guides is very diffused, in which, for the engagement with the transported articles, freely rolling elements are provided for, typically arrays of idle rollers.
In particular, “bilateral” roller guides are known, having a double face, with two opposite operative surfaces, both intended to engage the transported articles: such guides are intended to be used as dividing central walls, to divide a single flow of transported articles into two or more separate flows, for instance generically parallel. In general, the known bilateral roller guides are made up of two arrays of idle rollers, set close to each other: a first and a second ideal surfaces, tangent externally to the rollers of the first and, respectively, the second array, form the first and the second operative surfaces of the guide. Examples of bilateral guides are provided in the European patent applications EP 0 888 985 and EP 0 893 373, and in the Swiss patent 637 084.
The roller guides are generally preferred to another type of guides, that could be defined as “static”, not having rolling elements and constituted of bars, tubular elements or longitudinally extended profiled elements, for instance of steel; in fact, roller guides, differently from static guides, allow a contact substantially without sliding with the transported articles, and this avoids possible decelerations, jams or falls of the transported articles or superficial damages (for example, small abrasions). Particularly, a problem exhibited by static guides resides in the inevitable braking action that they exert, due to the friction, on the transported articles they guide; such braking action translates into an undesired effect of bridging of the front of the flow of transported articles, that hinders the regular advancement of the articles along the transport path.
Typically, the guides, particularly the central guides, are mounted in overhanging way, by means of clamps, to respective support bars that extend vertically and that are in turn fixed to the frame of the conveyor.
A problem affecting the guides for conveyors of articles is constituted by the twisting that the guides can suffer in consequence of lateral forces, transversal to the extension of the transport path, that in use are exerted on them by the transported articles. Particularly, the central guides, due to the stresses received by the transported articles, can suffer from undesired side bendings, that jeopardize the regular operation of the conveyor, originating for example phenomena of bridging of the flow of transported articles. It is therefore important that the guides are sufficiently rigid, particularly to withstand transversal stresses without deforming.
In view of the state of the art outlined above, the inventor has faced the problem of devising a guide for conveyor of articles that exhibited an improved resistance against bendings.